The text in L'Osservatore gives the date as January 29, 1987.
However, in
Bp. Zanic's July 1987
declaration
the date of the press release
is given as January 9.
Fr. Sivric's
The Hidden Side of Medjugorje
mentions
the same January 9 date.

January 1987: Communique of Yugoslav bishops concerning the facts of Medjugorje

We publish below the text of a communique published in the Official
Bulletin of the Archdiocese of Zagreb, I, 1987, p. 33,
signed by His Eminence Cardinal Franjo Kuharic, President of the
Yugoslav Episcopal Conference, and H.E. Most Rev. Pavao Zanic,
Bishop of Mostar-Duvno, concerning the facts of Medjugorje.

In
conformity with the canonical norms concerning the discernment
of alleged apparitions and private revelations, the
diocesan commission instituted for that purpose by the Bishop of Mostar,
Ordinary of the place, has conducted an inquiry into the events of Medjugorje.

In the course of the
investigation it emerged that the events in question went
far beyond the diocese in question. Consequently,
on the basis of the above-mentioned norms it seemed fitting to continue the
investigation on the level of
the Episcopal Conference with the institution of a new Commission for that
purpose.

The
Congregation for the Doctrine of the Faith was informed.
It expressed its appreciation for the work
carried out by the diocesan commission under the responsibility of
the local Ordinary, and it encouraged the continuance of the work
at the national episcopal level.

The
Episcopal Conference, therefore, is establishing a commission to
continue the investigation of the events at Medjugorje.
While awaiting the results of the commission's investigation
and the Church's judgement, pastors and faithful should observe an attitude
of prudence customary in such situations.
Therefore, it is not permissible to organize
pilgrimages and other manifestations motivated by the
supernatural character attributed to the events of Medjugorje.
Legitimate devotion to Our Lady, recommended by the Church,
must conform to the directives of the Magisterium and
especially to those contained in the Apostolic Exhortation
Marialis Cultus of 2 February 1974
(cf. AAS, 66, 1974, pp. 113-168).